1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 */
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/delay.h>
9 #include <linux/gpio.h>
10 #include <linux/io.h>
11 #include <asm/proc-fns.h>
12
13 #include <mach/regs-ost.h>
14 #include <mach/reset.h>
15
16 unsigned int reset_status;
17 EXPORT_SYMBOL(reset_status);
18
19 static void do_hw_reset(void);
20
21 static int reset_gpio = -1;
22
init_gpio_reset(int gpio,int output,int level)23 int init_gpio_reset(int gpio, int output, int level)
24 {
25 int rc;
26
27 rc = gpio_request(gpio, "reset generator");
28 if (rc) {
29 printk(KERN_ERR "Can't request reset_gpio\n");
30 goto out;
31 }
32
33 if (output)
34 rc = gpio_direction_output(gpio, level);
35 else
36 rc = gpio_direction_input(gpio);
37 if (rc) {
38 printk(KERN_ERR "Can't configure reset_gpio\n");
39 gpio_free(gpio);
40 goto out;
41 }
42
43 out:
44 if (!rc)
45 reset_gpio = gpio;
46
47 return rc;
48 }
49
50 /*
51 * Trigger GPIO reset.
52 * This covers various types of logic connecting gpio pin
53 * to RESET pins (nRESET or GPIO_RESET):
54 */
do_gpio_reset(void)55 static void do_gpio_reset(void)
56 {
57 BUG_ON(reset_gpio == -1);
58
59 /* drive it low */
60 gpio_direction_output(reset_gpio, 0);
61 mdelay(2);
62 /* rising edge or drive high */
63 gpio_set_value(reset_gpio, 1);
64 mdelay(2);
65 /* falling edge */
66 gpio_set_value(reset_gpio, 0);
67
68 /* give it some time */
69 mdelay(10);
70
71 WARN_ON(1);
72 /* fallback */
73 do_hw_reset();
74 }
75
do_hw_reset(void)76 static void do_hw_reset(void)
77 {
78 /* Initialize the watchdog and let it fire */
79 OWER = OWER_WME;
80 OSSR = OSSR_M3;
81 OSMR3 = OSCR + 368640; /* ... in 100 ms */
82 }
83
arch_reset(char mode,const char * cmd)84 void arch_reset(char mode, const char *cmd)
85 {
86 clear_reset_status(RESET_STATUS_ALL);
87
88 switch (mode) {
89 case 's':
90 /* Jump into ROM at address 0 */
91 cpu_reset(0);
92 break;
93 case 'g':
94 do_gpio_reset();
95 break;
96 case 'h':
97 default:
98 do_hw_reset();
99 break;
100 }
101 }
102
103